1. Field of the Invention
The present invention is directed to a system for translating hardcopy clinical patient signals into an electronic format that can be analyzed by a computer, stored, and later displayed in graphical form remotely over a computer network. More particularly, the present invention is directed to a software application that enables hardcopy Electroencephalogram (EEG) and Electrocardiogram (ECG) charts to be converted into an electronic format that can be received, analyzed, and stored by a Web server, and then transmitted to a Web browser upon request.
2. Description of the Prior Art
In a typical primary care physician's office (or even in some acute care units at hospitals) ECG tests are performed on patients. These tests are typically performed using the standard 3- or 12-lead methods in which a pen records the time-varying ECG signal on a paper strip. These devices are sometimes called “paper strip recorders.”
The paper strip is normally attached to the patient's permanent record (included in hardcopy format in the patient's folder). While this method is indeed cost effective and simple, it is transportable only in hardcopy format from the primary care physician to any referred physician or other health care provider. For instance, if a patient is referred to a specialist who will require a copy of the ECG, the hardcopy will either need to be sent beforehand or the patient will need to carry a copy of the hardcopy record with him or her to the referred physician's location. Alternately, the primary care physician can send an electronic facsimile of the ECG record to the recipient physician (or hospital, or surgical center, etc.). This obviates the need to carry hardcopy. However, the copy is still retrieved on the receiving end in hardcopy format only.
While analyzing an ECG waveform is a relatively simple task, it is often worthwhile to perform analysis on the waveform or to store the waveform in an electronic repository for remote viewing, later viewing, or off-line and remote on-line analysis. Hardcopy ECG records cannot be analyzed automatically, nor can they be transformed easily into other electronically readable formats other than simple images files, such as bit maps or in JPEG (Joint Photographic Experts Group) format. These electronic formats, while easily transferable cannot be analyzed using on-line mathematical methods, in real time from a remote location.
Accordingly, a system is needed that is capable of producing Web-based rendering of ASCII (American Standard Code for Information Interchange) formatted ECG data, and then transforming and analyzing ECG paper strips automatically via electronic means, which is developed using conventional development programming languages, such as standard C++ and Visual Basic, so that it can be easily integrated into existing software systems. Research into prior or related art reveals that some existing functionality in the area of image scanning and plotting is available on the open market. Specifically, existing art relating to the following functionality is available. For example, relative to transforming hardcopy graphs into electronic (or ASCII) data, Un-Scan-It by Silk Scientific Software (www.SilkScientific.com) is a representative product that enables reading hardcopy (x, y) graphs from scanners and extracting the component coordinates of the plot curve. Silk Scientific advertises on their Web page that allows a user to automatically convert hard copy graphs to (x,y) ASCII data at Full Scanner Resolution. UN-SCAN-IT works with any full page scanner, hand scanner, or other image input device to digitize strip charts, instrumental output, old graphs, published graphs, etc. In addition to the many digitizing features, UN-SCAN-IT also integrates peak areas, smooths data, takes derivatives, re-scales graphs, and exports (x,y) ASCII data for use in other software programs. Another example is an existing modification to a method described by Marv Luse in Bitmapped Graphics Programming in C++ relative to reading bitmap images) extracts the ASCII (x,y) coordinates of a bitmap image. The method for opening the image file was adapted from an existing piece of software by Luse in order to accomplish this latter function. A method also exists for reading bitmap images using Java code for the purpose of altering the images and is described by Joseph L. Webber in Special Edition Using Java 2 Platform Copyright 1999 by QUE. However, these systems of the prior art have several significant disadvantages. A system is needed that is portable, and integrates directly with standard word processing tools (such as Microsoft Excel and Word); and that performs processing on a server platform and delivers the finished plot to a client, in accord with the details specified in the claims.
The ability to display plots of ASCII (x, y) data on client platforms using client-side interpreted code, such as JavaScript or VB Script, is described by Ronald H. Nicholson in a JavaScript Plotter published in 1996. The functions developed by Nicholson may be used to create a server-side version of the plot specifically designed to read ASCII data (as opposed to operating on hard-coded functions, as is described in Nicholson's code) and to plot the coordinates of an ECG trace within a Web browser window. For reference purposes, this method will be termed the Server-Side Plotting Utility, or SSPU. An additional utility may also be developed that transmits ASCII coordinate data to a client, where a Java applet then reads the data and plots them within the Web browser window. For reference purposes, this method will be termed the applet Plotting Utility, or APU.
The needed advantages described above can then be accomplished in two ways: raw ASCII (x, y) data can be written to an array on the Server and are transformed into a plot within the client's HTML (Hyper Text Markup Language) page, such as by using an SSPU; or, raw ASCII (x, y) data can be written directly to the client where they are interpreted by a client-side function that performs the process of plotting, such as by using an APU